Excerpt from IMD (0900h, 29July2015)
'The depression over northeast Bay of Bengal and adjoining coastal areas of Bangladesh & West Bengal moved southeastwards, concentrated into a deep depression and lay centred at 0530 hours IST of today, the 29th July, 2015 over north east Bay of Bengal and adjoining areas of Bangladesh near Lat. 21.0 ° N and Long. 91.0 °E, 160 km south southwest of Chittagong (Bangladesh). The system would move nearly northward and cross Bangladesh Coast on 30th forenoon between Long. 90.5 °E and 91.5 °E.'
NB: Italics are mine.